For many years heat treating furnaces, refractory furnaces, ceramic kilns, brick kilns, and the like, were lined with thick dense refractory brick or blocks, and more recently, many of such furnaces are lined with cement-like materials such as gunite to protect the walls from extreme heat within the furnace. In constructing a cement-like insulation lining for the furnace wall, it is a common practice to spray coat a desired thickness of cement-like material thereon to form a substantially monolithic insulation lining with a plurality of spaced devices such as wire hangers mounted on metal studs welded to the furnace wall being employed for anchoring the insulation lining. Typically, the wire hangers employed as anchors are in the form of elongated lengths of wire mounted at a central point on welded studs with the opposite free ends thereof projecting inwardly from the furnace wall. The wire hangers are secured to the studs by nuts or the like which engage the free end, generally threaded, of the studs. During the course of time, it is also necessary to remove the old insulation material and replace the hangers before relining the furnace as they will deteriorate during use.
The spray application method of insulating refractory furnace walls involves considerable skill, labor and time to achieve an insulation lining with a substantially uniform thickness and surface which is securely anchored. It is generally required to individually position and weld the wire hanger studs to the surface of the wall to be protected and to secure the elongated wire hangers to the studs, the arrangement of wire hanger devices being important to insure that the entire furnace wall surface is protected. Thus, even through conventional welding techniques may be employed, the arrangement and placement of wire hangers involves considerable time and labor in new installations or in relining a furnace.
Spray application of cement-like insulation to the refractory furnace wall involves considerable skill and time to achieve the desired thickness and surface condition of the coating. Moreover, the process can be hazardous to the personnel involved in the operation, as well as being wasteful as to the insulation materials, since considerable quantities thereof may drop from the wall and accumulate on the floor. Needless to say, the furnace must be shut down and is out of operation during the extended periods of time needed to effect the insulation installation or replacement.